We present the design, realization and test of a high bit-rate optical communication system dedicated to underwater operations at the bottom of the sea transmitting data between sensor hubs and remote operated vehicles.
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In this paper, the attenuation of free space optical (FSO) communication systems operating at selected wavelengths of 0.83 μm, 1.31 μm and 1.55 μm in the controlled laboratory based fog and smoke environments are compared. The fog and smoke are generated and controlled homogeneously along the indoor atmospheric chamber of length 6 m. The experimental results from the selected wavelengths are compa...
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We realized and monitored over 72 hours a 1.25 Gbit/s FSO link, 320 m long, using novel transparent terminals. For the first time, we obtained 99.9992% availability and derived a statistical analysis of BER and scintillation index.
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Optical beams are highly affected by an atmosphere. Time and spatially variable distribution of the refractive index as well as different weather conditions result in fluctuation and attenuation of the optical beam. In order to improve signal reception, several mitigation techniques were developed for instance spatial diversity, auto-tracking, adaptive optics etc. This paper discusses utilization ...
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In this paper we propose a novel indoor optical wireless system for personal area networks based on MEMS mirrors and image sensors. The tracking system allows full user mobility and the directed link configuration guarantees high bit rates and energy efficiency due to the narrow beams. We make a simple simulation to analyze the bit error rate in dependence on the received power and beam spot size.
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This paper reports a study of different metrics to measure the performance of different MIMO Optical Wireless geometries. Signal to Interference Noise Ratio (SINR) is found to be the most appropriate metric of those studied. The reported simulation results also illustrate that overall system performance can be approximated to that of the worst MIMO sub-channel.
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Organic light emitting diodes (OLEDs) are an attractive proposition for replacing large area Lambertian sources in lighting systems. In this paper we investigate both illumination and communication properties of OLED based lighting configurations in a typical room. Two lighting designs are introduced and compared by deterministic and Monte-Carlo simulations. These show that there is considerable p...
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This paper investigates the requirements for uniform illumination using white LEDs, showing the balance between lighting and visible light communications. The communications system performance of the is also investigated for mobility with a varying field of view at the receiver, showing that there is a limit that beyond which there are no longer gains to be made in mobility.
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In this paper, we study an Optical Wireless Communication system for indoor healthcare monitoring application, taking into account the impact of indoor environment. We consider a diffuse link between an emitter placed on a mobile monitored patient and a base station located on the ceiling considering a one-bounce model. Thanks to Ray Propagation Simulator (RaPSor) developed at the Xlim-SIC laborat...
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A technique is presented which improves the performance of an optical receiver for optical wireless communication with a moderate additional complexity. The well-known high-impedance front-end design of an optical receiver is extended by combining multiple PIN photodiode-FET circuits with optimized equalizers in order to achieve a better SNR at the output of the receiver. The receiver is optimum i...
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Recently, a new and generalized statistical model, called M or Málaga distribution, has been proposed to model the irradiance fluctuations of an unbounded optical wavefront (plane and spherical waves) propagating through a turbulent medium under all irradiance fluctuation conditions in homogeneous, isotropic turbulence. The major advantage of the model is that leads to closed-form and mathematical...
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Free Space Optics (FSO) links are affected by several impairments: optical turbulence, scattering, absorption, and pointing. In particular, atmospheric optical turbulence generates optical power fluctuations at the receiver that can degrade communications with fading events, especially, in high data rate links. A way to mitigate FSO link outages can be to add a coding to communications. Neverthele...
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For an underwater wireless optical communication system, we consider the use of different intensity modulation techniques, and compare their performance by taking realistic system parameters into account. In particular, we contrast the performances of on-off keying, pulse position modulation, pulse width modulation, and digital pulse interval modulation, when a PIN or an avalanche photodiode is us...
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Transmittance for a Dense Wavelength Division Multiplexing (DWDM) system operating in non-Kolmogorov medium is evaluated. MODTRAN (MODerate resolution atmospheric TRANsmission) is also used to include the absorption and scattering effects due to atmospheric gases, aerosols and molecules. Increase in the power law of the non-Kolmogorov spectrum is found to decrease the transmittance at all the wave...
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For the case of multiple-input multiple-output (MIMO) free-space optical (FSO) communication systems, we consider the suitability of the spatial multiplexing scheme when on-off keying modulation is employed. We show that, even with the optimal maximum likelihood detection at the receiver, the performance is worse, compared to the case of repetition coding (RC) under the condition of equal transmis...
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We propose an over-gigabit visible light indoor transmission system employing a quasi-phase-matching (QPM) device. To enhance the transmission characteristic of the proposed system, we employ a collecting lens at the receiver (Rx). The applicability to over-gigabit indoor visible light transmission was investigated with a 1 and 2 m free space transmission experiments. The experimental results conf...
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